A sensor fastening method and a sensor fastening frame for use therewith are provided. The sensor fastening frame is coupled to a motor stator of a brushless motor having distributed coils and extends over the distributed coils to allow the sensor fastening frame to rotate about the axle of a motor rotor, without interference with the distributed coils. At least a sensor is fastened in position to the sensor fastening frame proximate to one end of the axle of the motor stator for positioning the sensor to detect magnetic field variations of the motor rotor.